2 * Copyright (c) 2008, Christoph Hellwig
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
21 #include "xfs_bmap_btree.h"
22 #include "xfs_inode.h"
23 #include "xfs_vnodeops.h"
24 #include "xfs_trace.h"
25 #include <linux/slab.h>
26 #include <linux/xattr.h>
27 #include <linux/posix_acl_xattr.h>
32 * - all ACL updates are protected by inode->i_mutex, which is taken before
33 * calling into this file.
36 STATIC struct posix_acl *
37 xfs_acl_from_disk(struct xfs_acl *aclp)
39 struct posix_acl_entry *acl_e;
40 struct posix_acl *acl;
41 struct xfs_acl_entry *ace;
42 unsigned int count, i;
44 count = be32_to_cpu(aclp->acl_cnt);
45 if (count > XFS_ACL_MAX_ENTRIES)
46 return ERR_PTR(-EFSCORRUPTED);
48 acl = posix_acl_alloc(count, GFP_KERNEL);
50 return ERR_PTR(-ENOMEM);
52 for (i = 0; i < count; i++) {
53 acl_e = &acl->a_entries[i];
54 ace = &aclp->acl_entry[i];
57 * The tag is 32 bits on disk and 16 bits in core.
59 * Because every access to it goes through the core
60 * format first this is not a problem.
62 acl_e->e_tag = be32_to_cpu(ace->ae_tag);
63 acl_e->e_perm = be16_to_cpu(ace->ae_perm);
65 switch (acl_e->e_tag) {
68 acl_e->e_id = be32_to_cpu(ace->ae_id);
74 acl_e->e_id = ACL_UNDEFINED_ID;
83 posix_acl_release(acl);
84 return ERR_PTR(-EINVAL);
88 xfs_acl_to_disk(struct xfs_acl *aclp, const struct posix_acl *acl)
90 const struct posix_acl_entry *acl_e;
91 struct xfs_acl_entry *ace;
94 aclp->acl_cnt = cpu_to_be32(acl->a_count);
95 for (i = 0; i < acl->a_count; i++) {
96 ace = &aclp->acl_entry[i];
97 acl_e = &acl->a_entries[i];
99 ace->ae_tag = cpu_to_be32(acl_e->e_tag);
100 ace->ae_id = cpu_to_be32(acl_e->e_id);
101 ace->ae_perm = cpu_to_be16(acl_e->e_perm);
106 xfs_get_acl(struct inode *inode, int type)
108 struct xfs_inode *ip = XFS_I(inode);
109 struct posix_acl *acl;
110 struct xfs_acl *xfs_acl;
111 int len = sizeof(struct xfs_acl);
112 unsigned char *ea_name;
115 acl = get_cached_acl(inode, type);
116 if (acl != ACL_NOT_CACHED)
119 trace_xfs_get_acl(ip);
122 case ACL_TYPE_ACCESS:
123 ea_name = SGI_ACL_FILE;
125 case ACL_TYPE_DEFAULT:
126 ea_name = SGI_ACL_DEFAULT;
133 * If we have a cached ACLs value just return it, not need to
134 * go out to the disk.
137 xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
139 return ERR_PTR(-ENOMEM);
141 error = -xfs_attr_get(ip, ea_name, (unsigned char *)xfs_acl,
145 * If the attribute doesn't exist make sure we have a negative
146 * cache entry, for any other error assume it is transient and
147 * leave the cache entry as ACL_NOT_CACHED.
149 if (error == -ENOATTR) {
151 goto out_update_cache;
156 acl = xfs_acl_from_disk(xfs_acl);
161 set_cached_acl(inode, type, acl);
168 xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl)
170 struct xfs_inode *ip = XFS_I(inode);
171 unsigned char *ea_name;
174 if (S_ISLNK(inode->i_mode))
178 case ACL_TYPE_ACCESS:
179 ea_name = SGI_ACL_FILE;
181 case ACL_TYPE_DEFAULT:
182 if (!S_ISDIR(inode->i_mode))
183 return acl ? -EACCES : 0;
184 ea_name = SGI_ACL_DEFAULT;
191 struct xfs_acl *xfs_acl;
194 xfs_acl = kzalloc(sizeof(struct xfs_acl), GFP_KERNEL);
198 xfs_acl_to_disk(xfs_acl, acl);
199 len = sizeof(struct xfs_acl) -
200 (sizeof(struct xfs_acl_entry) *
201 (XFS_ACL_MAX_ENTRIES - acl->a_count));
203 error = -xfs_attr_set(ip, ea_name, (unsigned char *)xfs_acl,
209 * A NULL ACL argument means we want to remove the ACL.
211 error = -xfs_attr_remove(ip, ea_name, ATTR_ROOT);
214 * If the attribute didn't exist to start with that's fine.
216 if (error == -ENOATTR)
221 set_cached_acl(inode, type, acl);
226 xfs_set_mode(struct dentry *dentry, struct inode *inode, umode_t mode)
230 if (mode != inode->i_mode) {
233 iattr.ia_valid = ATTR_MODE | ATTR_CTIME;
234 iattr.ia_mode = mode;
235 iattr.ia_ctime = current_fs_time(inode->i_sb);
237 error = -xfs_setattr_nonsize(dentry, XFS_I(inode), &iattr,
245 xfs_acl_exists(struct inode *inode, unsigned char *name)
247 int len = sizeof(struct xfs_acl);
249 return (xfs_attr_get(XFS_I(inode), name, NULL, &len,
250 ATTR_ROOT|ATTR_KERNOVAL) == 0);
254 posix_acl_access_exists(struct inode *inode)
256 return xfs_acl_exists(inode, SGI_ACL_FILE);
260 posix_acl_default_exists(struct inode *inode)
262 if (!S_ISDIR(inode->i_mode))
264 return xfs_acl_exists(inode, SGI_ACL_DEFAULT);
268 * No need for i_mutex because the inode is not yet exposed to the VFS.
271 xfs_inherit_acl(struct inode *inode, struct posix_acl *acl)
273 umode_t mode = inode->i_mode;
274 int error = 0, inherit = 0;
276 if (S_ISDIR(inode->i_mode)) {
277 error = xfs_set_acl(inode, ACL_TYPE_DEFAULT, acl);
282 error = posix_acl_create(&acl, GFP_KERNEL, &mode);
287 * If posix_acl_create returns a positive value we need to
288 * inherit a permission that can't be represented using the Unix
289 * mode bits and we actually need to set an ACL.
294 error = xfs_set_mode(NULL, inode, mode);
299 error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
302 posix_acl_release(acl);
307 xfs_acl_chmod(struct inode *inode)
309 struct posix_acl *acl;
312 if (S_ISLNK(inode->i_mode))
315 acl = xfs_get_acl(inode, ACL_TYPE_ACCESS);
316 if (IS_ERR(acl) || !acl)
319 error = posix_acl_chmod(&acl, GFP_KERNEL, inode->i_mode);
323 error = xfs_set_acl(inode, ACL_TYPE_ACCESS, acl);
324 posix_acl_release(acl);
329 xfs_xattr_acl_get(struct dentry *dentry, const char *name,
330 void *value, size_t size, int type)
332 struct posix_acl *acl;
335 acl = xfs_get_acl(dentry->d_inode, type);
341 error = posix_acl_to_xattr(acl, value, size);
342 posix_acl_release(acl);
348 xfs_xattr_acl_set(struct dentry *dentry, const char *name,
349 const void *value, size_t size, int flags, int type)
351 struct inode *inode = dentry->d_inode;
352 struct posix_acl *acl = NULL;
355 if (flags & XATTR_CREATE)
357 if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
358 return value ? -EACCES : 0;
359 if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
365 acl = posix_acl_from_xattr(value, size);
368 * acl_set_file(3) may request that we set default ACLs with
369 * zero length -- defend (gracefully) against that here.
374 error = PTR_ERR(acl);
378 error = posix_acl_valid(acl);
383 if (acl->a_count > XFS_ACL_MAX_ENTRIES)
386 if (type == ACL_TYPE_ACCESS) {
387 struct posix_acl *saved_acl = acl;
390 error = posix_acl_update_mode(inode, &mode, &acl);
391 if (error || acl == NULL)
392 posix_acl_release(saved_acl);
395 error = xfs_set_mode(dentry, inode, mode);
401 error = xfs_set_acl(inode, type, acl);
403 posix_acl_release(acl);
408 const struct xattr_handler xfs_xattr_acl_access_handler = {
409 .prefix = POSIX_ACL_XATTR_ACCESS,
410 .flags = ACL_TYPE_ACCESS,
411 .get = xfs_xattr_acl_get,
412 .set = xfs_xattr_acl_set,
415 const struct xattr_handler xfs_xattr_acl_default_handler = {
416 .prefix = POSIX_ACL_XATTR_DEFAULT,
417 .flags = ACL_TYPE_DEFAULT,
418 .get = xfs_xattr_acl_get,
419 .set = xfs_xattr_acl_set,